Fluid containers



June 1 1957 A. MATHISEN 7 ,79 2

FLUID CONTAINERS Filed Aug. 24, 1955 2 Shets-Sheet 1 a g EEO], 38 y IE0a /IJ 4 \H 39 44a a: 12a 34 a 3kg l6 INVENTOR Mons Mums.

A. MATHISEN FLUID CONTAINERS June 11, 1957 2 Sheets-Sheet 2 Filed Aug.24, 1955 INVENTQQ h in; Mmmn FLUID CONTAINERS Anders Mathisen, London,England, assignor of one-half to Groviner Manufacturing Company Limited,and one-half to Wilkinson Sword Limited, London, England, both Britishcompanies Application August 24,- 1955, Serial No. 530,226

Claims priority, application Great Britain September 3, 1954 13 Qiaims.(Ci; 1 69--9) This application is in part a continuation of my priorapplication Serial No. 456,719, filed September 17, 1954.

This invention relates to fluid containers, and pariicularly, though notexclusively, relates to devices for containing liquids adapted toextinguish fires or suppress explosions, the devices being of the kindin which a pressurised gas is used to efiect ejection of the liquid. IAccording to the present invention there is provided a liquid containerof the kind in which a pressurised gas is used to effect ejection of theliquid through a normallysea-led discharge outlet, comprisingelectrically operated ,7

means for unsealing said outlet, means for retaining the pressurised gasout of contact with the liquid prior to the time when discharge isrequired, and means operated substantial-1y simultaneously with saidorifice unsealing means for allowing the pressurised gas to act upon theliquid to effect discharge.

The invention also provides 'aliquid container of the kind in which apressurised gas is used to effect ejection of the liquid, comprising areservoir for the liquid having a sealed discharge outlet, a reservoirfor the gas, 2. nor- United States atent ma-lly-sealed interconnectionbeing provided between said gas reservoir and said liquid reservoir,electrically operated means for unsealing said discharge outlet andfurther means for substantially simultaneously unsealing saidinterconnection whereby said pressurised gas is freed to effect ejectionof liquid in said liquid reservoir through .said discharge outlet.

There is further provided in accordance with the inven- "tion a liquidcontainer comprising a liquid reservoir, a -discharge outlet from saidreservoir, frangible :rn'eans sealing said discharge outlet, anelectrically ignitable explosive charge for fracturing said frangiblemeans to unseal said discharge outlet, a reservoir for pressurised gas.used to effect ejection of liquid from said reservoir :through saiddischarge outlet, an outlet for gas from said gas reservoir throughwhich gas can pass into said liquid reservoir, further frangible means"sealing the outlet from :the gas reservoir, said -further frangiblemeans being fractured upon ignition of -said explosive charge, and apiston movable within said liquid reservoir, the arrangement being suchthat when the gas reservoir outlet "is unsealed by ignition of saidexplosive charge the pres- :su'rised gas acts on one side of the pistonwhose other whilst Figure 2 is a similar *view o f' t he "secondconstruction,

Figure 3 is a detail view of the discharge end of the construction shownin Figure 2, and

Figures 4 and 5 are two views of the discharge end of the Figure 2construction illustrating operation of the container.

Referring now to Figure 1, this shows an extinguisher 10 having a liquidreservoir 10a and a discharge orifice 11 which is normally sealed by astopper member 12 formed integrally with the extinguisher head 13, thestopper member 12 being connected thereto by a thin frangible web 1201.A removable electrically-fired explosive charge 14 is secured in thehead 13 and the explosive force resulting from ignition ofthe charge 14enters the space 15 and acts upon the stopper member 12 urging itdownwards towards the discharge orifice 11 and severing the frangibleweb 12a. The stopper member 12 is driven into the cup portion 16 belowthe discharge orifice llthereby allowing a free discharge of fluidthrough the neckof the extinguisher and out through the dischargeorifice 11. The discharge orifice end of the extinguisher as thusdescribed is similar to earlier constructions of the applicants but theother end of the bottle is entirely different and is modified to providea closed spherical reservoir 17 for the pressurised gas. A centralaperture is provided inthe side of the gas reservoir 17 which faces intothe interior of the reservoir 10a, and in this aperture is sealedaftubelS which extends into the gas reservoir 17 and is coaxial with thelongitudinal axis of the extinguisher 10. The end of the tube 18 whichlies within the reservoir 17 is closed by a sealing member 19 whichincludes a thin frangible web 19a and which is provided with are-entrant shoulder 19b. The stopper member 12 is united to one end of-atie rod 20 which extends through the extinguisher and through the tube18 and has its other end 20a lying within the reservoir sealing member19 and trapped behind the re-entrant shoulder 1%. An apertured annularmember 21 is secured in the tube 18 adjacent the wall of the gasreservoir 17 and forms a guide for the tie rod 20. A cup-shaped sheetmetal piston 22, which may be of beryllium copper, is formed with a thinskirt split at numerous points around the circumference to permitflexible engagement of the skirt with the interior of the side wall ofthe extinguisher. The piston 22 is formed with a central aperture inwhich a guide tube 23 :is secured, the guide tube 23 being a sliding fiton the tie rod 20. The piston 22 is normally positioned adjacent the gas'reservoir 17 with its concave surface facing the reservoir 17,, and maybe positively located in this position by a simple spring catch '24provided on the piston guide tube 23 and engaging a locating groove 20bon the tie rod 2i :By this construction the pressurising gas and theliquid suppressant are kept separate until the explosive charge 14 isfired to sever the stopper member 12 "sealing the discharge orifice. Theonly added restraint to initial movement of the stopper member 12 is dueto the inertia of the tie rod 20, as the construction is such that thetrapped end 20a of the tie rod 20 is free to move for a short'distancebefore coming into engagement with the re-entrant shoulder 1%. However,this engagement occurs after a short movement of the stopper member 12,and further movement of the tie rod '20 fractures the frangible web 19aof the reservoir sealing member 19. The pressurising gas is thus freedto act upon the piston 22 and thereby .force the suppressant out of theextinguisher through the orifice 11. The piston 22 serves to maintainthe separation between the gas and liquid and will move down theextinguisher as the suppressant is ejected, the piston 22 being guidedin its passage by engagement of the piston guide tube 23 with the tierod 20. As the piston 22 nears the end of its travel the piston guidetube 23 reaches a portion of the tie rod 20c which is of reducedcross-section, and the gas can then by-pass the piston 22 and maintainthe discharge of the suppressant not only until the extinguisher isempty but also through any pipe line which may be connected to thedischarge orifice 11.

A similar construction is also possible where the extinguisher has dualdischarge orifices which commence together at the neck of the bottle andare inclined outwardly to one another. It-is not readily possible to.provide a rigid connection between both stopper member and the tie rod,in view of the fact that with outward movement of the stopper memberthey move further apart from one another. However, this difiiculty canbe overcome by arranging that the connection between the bot tom of thetie rod and each stopper member is a fiexible one or is a linkage whichis automatically disconnected, after the orifice sealing the gasreservoir has been opened, as a result of further outward movement ofthe stopper member.

With the majority of existing extinguishers used in aircraft, thepositions in which the extinguisher can be mounted are very limited dueto the fact that in other positions it is possible for the pressurisinggas to escape before some or all of the liquid suppressant, with theresult that the latter is not ejected. Thus, in general in order toensure eifective discharge it is necessary for the discharge orifice tobe lowermost at the time of dis charge. However, even if anyextinguisher is mounted so that its discharge opening is lowermost whenthe aircraft is in its normal flight or ground attitude, the orientationof the aircraft as the result of a crash may be such that at the time ofdischarge the discharge opening is not lowermost and efiective dischargemay not occur.-

This limitation regarding mounting of the extinguisher does not apply tothe construction described above, for the reason that the gas is keptseparate from the liquid until the great majority of the liquid has beenejected, and this means that whatever the attitude of the extinguisherat the time of discharge the gas cannot escape past the liquid, at leastto any significant extent. Extinguishers according to the invention aretherefore suitable for use in aircraft crash protection installationswhere vertical mounting of the extinguisher is not possible, or at leastnot desirable, for example in aircraft wings of thin section where suchextinguishers may be mounted horizontally or in some other attitudeinclined to the vertical.

Separation of the gas and liquid means that only the gas reservoir needbe sufiiciently strong to resist the high gas pressure which may be asmuch as 350 pounds per square inch or even more. The strength of theliquid compartment is determined by the fact that prior to operation itswalls are only required to resist the much lower liquid vapour pressure(which increases with rising temperature), although subsequently theywill have to resist the pressure existing when the gas is firstreleased. Clearly for the same weight as an extinguisher having theliquid and gas in communication, the initial pressure or the maximumsafe operating temperature may be increased. It should be noted that ina space occupied by a mixture of vapour and a gas which do not reactchemically, each exerts the pressure which it would produce if it aloneoccupied the space. The total pressure when the gas and liquid are notseparated is therefore equal to the sum of the vapour pressure and thegas pressure. However, by separating the gas and liquid in the mannerdescribed the maximum pressure on the gas reservoir is that due to thegas alone, whilst the maximum pressure onjthe remainder of the containeris that due to the vapour pressure of the liquid alone.

It will now be apparent that even in cases where there is no advantagein separating the gas and liquid from the viewpoint of the mountingposition of the extinguisher,

such separation may still be desirable in order to obtain the abovedescribed advantages regarding pressures. The piston used in the abovedescribed construction may be omitted where separation is not requiredafter the commencement of discharge.

Whilst in the above described construction there are obvious advantagesin the use of a single cartridge to eflect opening of both gas andliquid orifices, it will be apparent that separate cartridges may beused to open each orifice, the cartridges being fired substantiallysimultaneously.

Referring now to Figures 2 and 3, these show the second construction inwhich the extinguisher is of broadly similar form to that shown inFigure 1, however, in this construction the discharge orifice 31 isclosed by a diaphragm sealing member or closure cap 32 which is openedby ignition of an electrically ignited explosive charge 34,.and theforce of the explosion used to burst open the closure cap 32 is alsoused to effect movement of a member 35 which will in turn release thegas from the gas reservoir 36 to act upon the liquid contents of theliquid reservoir 30a.

The explosive charge 34 is carried by a cartridge holder 44 mounted inthe head 45. The cartridge holder 44 extends into the middle of the neckof the extinguisher 30 and is designed to afford the minimum ofobstruction to discharging liquid. The cartridge holder 44 has a bore44a which at one end communicates with the ex plosive charge and at theother end terminates in a transverse portion 44b one end of which isclosed by a frangible housing 37 of thimble-shape. The thimble 37 ispositioned facing the closure cap 32 and is designed to resist thepressure resulting from ignition of the explosive charge 34 untilburning of the charge is substantially complete whereupon the thimble 37shatters to release the pent-up force of the explosion for bursting theclosure cap 32. The other end of the transverse bore 44b forms acylinder in which a piston-like member 38 is slidably mounted. Movementof the piston member 38 towards the thimble 37 is limited by a stoppin39. The end of the transverse bore 44b is sealed against the entry ofliquid by a bellows 40 which encloses the projecting end of the pistonmember 38. The end of the piston member 38 bears through the end of thebellows 40 against the member 35. The latter comprises a tube 35aprovided with a bearer 3512 at one end which is a sliding fit in a guidetube 41. The other end of the tube is carried by a member 350 which isalso a sliding fit in the guide tube 41 and is formed with a sharp punchor piercing portion 35a located opposite two abutting diaphragms 42 and43. The diaphragm 42 sealsthe end of the liquid reservoir 30a whilst thediaphragm 43 seals the spherical gas reservoir 36.

When the explosive charge 34 is fired, the resultant explosive force istransmitted through the bores 44a and 44b to burst the thimble 37 andcap 32 in the manner described above, and as shown in Figure 4. At thesame time the piston 38 is driven forward extending the bellows 40 anddriving the punch 35d through the two diaphragms 42 and 43.

Because the cutting edge of the punch 35d lies in a plane which is notnormal to the longitudinal axis of the member 35, the two diaphragms 42,43 do not have a portion cut out completely but a circular flap isformed in each which hinges about the uncut edge. The end of the punch35d is somewhat tapered so that it wedges in the diaphragms 42, 43 andrenders it unlikely that the flaps will be bent back and efiect partialre-closure of the opening formed. The gas passes through slots in thewall of the punch 35d and the guide tube 41 to act upon a piston 46which serves a similar purpose to that in the previous construction. Thepiston 46 comprises an inner cone 46a and an outer cone 46b from whichextend a number, for example twelve, of flexible metal ase 6 a nt onesof h h Par iall ove lap. By this construction the vanes 46c can besprung together sufficiently to pass the piston through the dischargeorifice end of the liquid reservoir 30 during as- Sombly. The inner cone46a is a sliding fit on the out- Side of the guide tube 41. The piston46 carries a plurality of spring clips 47 which prior to operation ofthe extinguisher engage slots formed in the member 35c, the end 47a ofeach clip 47 passing through a slot in the guide tube 41. Prior tooperation of the extinguisher the clips 47 serve to retain the piston 46at the end of the liquid reservoir and also serve to retain the membcr35 in correct position within the guide tube 41. When the member 35 ismoved by firing the cartridge, the end 47a of each clip 47 is driven outof engagement with the slot in the member 35c and the piston is thenfree to move down the guide tube 41. When the piston 46 reaches theother end of the guide tube 41 the gas can escape through slots 41a.

As already mentioned one of the advantages accruing from separation ofthe gas and liquid prior to discharge is that discharge will still occursatisfactorily irrespective of the orientation of the extinguisher atthe time of discharge. However, when the discharge orifice is sealedwith a diaphragm such as the cap 32 the explosive force is transmittedmore effectively to the cap if liquid is present between the thimble 37and the cap 32. But, in the absence of special provision mounting of theextinguisher in certain attitudes will mean that liquid is not presentin this space, or only part of the space contains liquid.

The possible reduction in effectiveness of the explosive charge in theabsence of liquid between the thimble 37 and the cap 32 may be offset byclosing the annular area which surrounds the thimble 37 behind the cap32 and through which the liquid passes during discharge. Clearly, thisarea must only be closed prior to bursting of the cap 32 so that freedischarge of the liquid contents of the extinguisher is possiblethereafter.

Numerous ways of achieving this are possible, but in the constructionshown in Figures 2 and 3 the closure means takes the form of an annulardisc 48. This disc 48 is provided with radial slits 48a (Figure 3) toform a number of petals, for example six, the slits 48a terminatingbefore the periphery of the disc so that the petals are attached to oneanother adjacent the periphery.

The disc 48 is reinforced by a supporting grid 49 positioned on the sideof the disc 48 remote from the cap 32. When the thimble 37 is burst thegrid 49 supports the petals against the force of the explosion as shownin Figure 4, the explosion being confined within the space between thecap 32 and the disc 48 so that virtually the full force of the explosionacts on the cap 32. When the cap 32 bursts the petals are exposed to thefull force of the pressurised liquid, and are thus bent back as shown inFigure 5 allowing free discharge of the liquid.

I claim:

1. A liquid container comprising a liquid reservoir, said liquidreservoir having a sealed discharge outlet, a gas reservoir forcontaining pressurised gas used to effect ejection of the liquid, saidgas reservoir and said liquid reservoir having a normally sealedintercommunicating orifice, electrically operated unsealing means forunsealing said liquid reservoir discharge outlet, and further unsealingmeans for unsealing said intercommunicating orifice between said gas andliquid reservoirs, and means actuated by said first mentioned unsealingmeans for operating said further unsealing means substantiallysimultaneously with the unsealing of said liquid reservoir dischargeoutlet whereby said pressurised gas is freed to effect ejection of theliquid in said liquid reservoir through said discharge outlet.

2. A liquid container comprising a liquid reservoir, said liquidreservoir having a discharge outlet, at frangible member sealing saiddischarge outlet, a gas reservoir for containing pressurised gas used toeffect ejection of the liquid, a further frangible member sealing saidgas reservoir from said liquid reservoir, an explosive charge, saidexplosive charge having electrical igniting means and being mounted inproximity to said frangible member for fracturing said frangible memberby the explosive force generated upon ignition of said charge to unsealsaid liquid reservoir discharge outlet, and a movable member forfracturing said further frangible member, when said movable member movesby a predetermined amount, said movable member being movable by saidpredetermined amount by the force generated upon ignition of saidexplosive charge whereby said pressurised gas is freed to effectejection of the liquid from said liquid reservoir through said dischargeoutlet.

3. A fire extinguisher comprising a reservoir for extinguishing liquid,said extinguishing liquid reservoir having a discharge outlet, afrangible member sealing said discharge outlet, a gas reservoir, afurther frangible member sealing said gas reservoir from said liquidreservoir, an explosive charge, said explosive charge having electricaligniting means for igniting said exposive charge to produce an explosiveforce, means 'for utilizing part of said explosive force to fracturesaid frangible member, further means for utilizing part of saidexplosive force to fracture said further frangible member substantiallysimultaneously with the fracturing of said first-mentioned frangiblemember, and a movable piston mounted in said liquid reservoir adjacentsaid further frangible member whereby when said further frangible memberis fractured the gas released from said gas reservoir moves said pistonalong said liquid reservoir to eject the extinguishing liquid throughsaid discharge outlet.

4. In a liquid container of the kind in which a pressurised gas is usedto effect ejection of the liquid through a normally-sealed dischargeoutlet, frangible means for sealing said outlet, an explosive charge,means for igniting said explosive charge, means for applying part of theexplosive force resulting from ignition of said charge to fracture saidfrangible outlet sealing means, a sealed gas reservoir having an orificecommunicating with the liquid container, frangible orifice sealing meansfor retaining the pressurised gas out of contact with the liquid priorto the time when discharge is required, and means for applying part ofsaid explosive force to fracture said frangible orifice sealing means.

5. A liquid container comprising a liquid reservoir, said reservoirhaving a discharge outlet for liquid, frangible means sealing saiddischarge outlet, an electrically ignitable explosive charge forfracturing said frangible means to unseal said discharge outlet, a gasreservoir, said gas reservoir having an outlet through which gas canpass into said liquid reservoir to effect ejection of liquid from saidreservoir through the discharge outlet of the liquid reservoir, furtherfrangible means sealing the gas reservoir outlet, means operable by saidexplosive charge for fracturing said further frangible means uponignition of said explosive charge, and a piston movable within saidliquid reservoir, whereby gas released from said gas reservoir as aresult of ignition of said explosive charge acts on the piston to movethe piston along the reservoir and thereby eject liquid through theliquid discharge outlet.

6. A liquid container according to claim 5, in which the liquidreservoir is of elongated cylindrical shape and the gas reservoir is ofspherical shape, the gas reservoir being mounted at one end of saidliquid reservoir and the discharge outlet being provided at the oppositeend of said liquid reservoir.

7. A liquid container according to claim 5, in which said piston iscomposed of a number of flexible metal vanes whereby the vanes can besprung together sufficiently to pass the piston through the liquiddischarge outlet during assembly of the container.

8. Aliqui-d container according to claim 7 in which adjacent vanesoverlap.

9. A liquid container comprising a liquid reservoir, said reservoirhaving a discharge outlet for liquid, 21 frangible diaphragm sealingsaid discharge outlet, and explosive charge having electrical ignitingmeans, a holder for said explosive charge, said holder having a boreterminating opposite said diaphragm, a frangible cover closing the endof said bore, a member closing the space around said frangible cover forconcentrating onto said frangible diaphragm a predetermined part of theforce of the explosion resulting from ignition of said explosivecharge,,a gas reservoir, said gas reservoir having an outlet throughwhich gas can pass into said liquid reservoir to effect ejection ofliquid from said reservoir through the discharge outlet of the liquidreservoir, further frangible means sealing the gas reservoir outlet,means for utilizing the remaining part of the force of the explosion forfracturing said further frangible means upon ignition of said explosivecharge, and a piston movable within said liquid reservoir, whereby gasreleased from said gas reservoir as a result of ignition of saidexplosive charge acts on the piston to move the piston along thereservoirand thereby eject liquid through the liquid discharge outlet;

10. A liquid container according to claim 9, in which a tube extendsthrough said liquid reservoir, and in which said means for utilizing theremaining part of the force of the explosion for fracturing said furtherfrangible means is a movable member slidably mounted within said tube,said piston having a hub slidable on the outside of said tube.

11. A liquid container according to claim 9, in which said memberclosing the space around the frangible cover comprises a disc, said discbeing weakened along predetermined lines, and in which a grid structuresupports said disc on the side opposite of the said facing into saidspace.

. .12. A fire extinguisher comprising a reservoir for extinguishingliquid, said extinguishing liquid reservoir having a discharge outletfor liquid, a frangible diaphragm sealing said discharge outlet, anelectrically ignitable explosive charge, a holder for said explosivecharge, said holder having a bore commencing adjacent said charge andterminating opposite said diaphragm, a frangible cover closing the endof said bore, a member closing the space around said frangible cover forretaining a pre-determined amount of the force of the explosion in theregion of said diaphragm prior to opening thereof, a gas reservoir, saidgas reservoir having an outlet through which gas can pass into saidliquid reservoir, further frangible means sealing the outlet from thegas reservoir, a movable member, a predetermined movement of saidmovable member fracturing said further frangible means, means forapplying part of the force of said explosion to said movable member toeffect said predetermined movement, and a movable piston mounted in saidliquid reservoir adjacent said further frangible member whereby gasreleased from said gas reservoir as a result of ignition of saidexplosive charge acts on the piston to move the piston along the liquidreservoir and thereby eject liquid through the liquid discharge outlet.

13. A fire extinguisher according to claim 12, in which said holder hasa further bore communicating with the first bore, and in which saidmeans for applying part of the force of said explosion to said movablemember comprises a plunger movable in said bore, said plunger contactingsaid movable member whereby part of the force of the explosion resultingfrom ignition of the explosive charge moves said plunger which in turnefiects movement of said movable member by said predetermined amount.

References Cited in the file of this patent UNITED STATES PATENTS2,582,112 Ferguson Jan. 8, 1952

